binman: Handle hidden symbols in ELF files

Some versions of binutils generate hidden symbols which are currently not
parsed by binman. Correct this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/elf.py b/tools/binman/elf.py
index c7ef74c..66cfe79 100644
--- a/tools/binman/elf.py
+++ b/tools/binman/elf.py
@@ -72,7 +72,7 @@
         parts = rest[7:].split()
         section, size =  parts[:2]
         if len(parts) > 2:
-            name = parts[2]
+            name = parts[2] if parts[2] != '.hidden' else parts[3]
             syms[name] = Symbol(section, int(value, 16), int(size,16),
                                 flags[1] == 'w')